CD163 immunohistochemistry is superior to CD68 in predicting outcome in classical Hodgkin lymphoma

• Published in: American journal of clinical pathology Vol. 141; no. 3; pp. 381 - 387
• Main Authors: Klein, Jonathan L, Nguyen, TuDung T, Bien-Willner, Gabriel A, Chen, Ling, Foyil, Kelley V, Bartlett, Nancy L, Duncavage, Eric J, Hassan, Anjum, Frater, John L, Kreisel, Friederike
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-03-2014
• Subjects: Adult; Antigens, CD - metabolism; Antigens, Differentiation, Myelomonocytic - metabolism; Biomarkers, Tumor - metabolism; Disease-Free Survival; Female; Hodgkin Disease - diagnosis; Hodgkin Disease - metabolism; Hodgkin Disease - mortality; Humans; Immunohistochemistry; Macrophages - metabolism; Male; Middle Aged; Prognosis; Receptors, Cell Surface - metabolism; Retrospective Studies; Survival Rate; Treatment Outcome; High IPS; CD163; Tumor-infiltrating macrophages; CD68; Overall survival; Classical Hodgkin lymphoma
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1309/ajcp61tlmxlsljys

In recent years, research has increasingly focused on the microenvironment of classical Hodgkin lymphoma (CHL) as a predictor of treatment outcome. The focus of this study was to assess the interobserver reproducibility in interpreting macrophage-associated immunohistochemistry (IHC) for CD68 and CD163 in a retrospective cohort of 88 patients with CHL.
Staining results were correlated with clinical outcome in all patients and those with a high international prognostic score (IPS).
The intraclass correlation (ICC) for the five hematopathologists interpreting the IHC was stronger for CD163 (0.70) than for CD68 (0.50). Using a cutoff of 25% mean macrophage reactivity and including all patients, a statistically significant difference in overall survival (OS) was seen only for CD163 (P = .0006) and not for CD68 (P = .414). Patients with a mean CD163 reactivity of 25% or more had a median OS of 71 months vs 101 months for patients with less than 25% reactivity. CD163 retained statistical significance in multivariate analysis. In patients with advanced-stage CHL with high IPS, OS was also significantly worse for those with a mean CD163 reactivity of 25% or higher.
Our study confirms previous reports of a prognostic role of tumor-infiltrating macrophages in CHL, but only for CD163. Although most of the literature supports an increasing role of macrophage IHC as a predictor of clinical outcome, successful clinical translation will require a standardized method and reporting system.